|Name|Position|Year|League apps|League goals|Total apps|Total goals|Notes|
|---|---|---|---|---|---|---|---|
|Walter Langton|LB / CF|1887–1905|45|28|48|48|Doncaster's longest serving player Appearance stats don't include seasons 1887–1901 nor 1903–04 which are likely to put his total appearances over 400|
|Tom Keetley|FW|1923–1929|231|180|241|186|Record all time goalscorer. Most goals in one game – 6 v Ashington in 1929|
|Fred Emery|WH|1924–1936|417|30|439|32|Record league appearances Manager of Doncaster 1936–1940|
|Paddy McConnell|IF|1925–1930|137|20|143|21|The first current Doncaster player to represent his country at international level, Paddy played for Ireland|
|Syd Bycroft|DF|1936–1951|333|2|355|2|Including Wartime League matches, he played 501 games for Doncaster giving him the overall all-time record number of appearances. Joint manager of Doncaster January–June 1958|
|Eddie Perry|CF|1936–1938?|98|44|102|?|Welsh international whilst at Doncaster|
|Clarrie Jordan|FW|1945–1948|60|48|67|50|Most Doncaster league goals in one season (42 in 1946/47)|
|Charlie Williams|DF|1948–1959|158|1|174|1|Famous comedian|
|Peter Doherty|IF|1949–1953|103|55|109|58|Ireland international player and manager of Northern Ireland whilst at Doncaster Manager of Doncaster 1949–1958 (PM until 1953)|
|Len Graham|MF|1949–1958|312|3|332|3|Northern Ireland international whilst at Doncaster|
|Kit Lawlor|IF|1950–1954|127|47|143|49|Republic of Ireland international whilst at Doncaster|
|Harry Gregg|GK|1952–1957|94|0|99|0|Northern Ireland international whilst at Doncaster. Hero of the Munich air disaster|
|Alick Jeffrey|FW|1954–1956, 1963–1968|262|129|293|140|Youngest Doncaster player (15 years 229 days v Fulham, 15 September 1954).|
|Colin Douglas|FW|1981–1986, 1988–1993|404|53|444|62|Record total appearances (not including the Wartime League games). Forward in his first spell, fullback in his second|
|Brian Stock|MF|2006–2012|193|18|216|23|Welsh international whilst at Doncaster|
|Billy Sharp|FW|2009–2012, 2014–|92|44|96|45|Record Transfer Fee Paid: £1,150,000|

Question: how many years did syd bycroft spend playing for doncaster?
Answer: 15